# SDR ASAA2023041242836

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 12, 2023
- Submitted: April 14, 2023
- Operation: Air carrier
- Aircraft: [N477AS](https://openairdocs.org/aircraft/N477AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 40716
- Aircraft time: 28,074 hours, 8,700 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Unknown
- Part number: UNKNOWN
- Condition: Unknown
- Location: Unknown
- Stage of operation: CR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2023041242836

## Discrepancy

AT FL360 ENGAGGED "A" AUTOPILOT. AFTER 5 MINUTES, AUTOPILOT DISENGAGED. RE-ENGAGED "A" AUTOPILOT, AND AFTER 5 MINUTES, AUTOPILOT DISENGAGED AGAIN. ENGAGED "B" AUTOPILOT, "B" WORKS FINE. GROUNDED - YES. ACCOMPLISHED DFCS BITE B737-900 FIM 22-11 TASK 801. FOUND FAULT " 22-11186 TRIM CMD RESPSE MON" ON CHANNEL A FLIGHT LEG 1 @ 36000 FT. ACCOMPLISHED FIM 22-11 TASK 854. ALL TESTS PASS. NO HISTORY PAS 30 DAYS.

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